Luogu3426 [POI2005]SZA-Template (KMP)（未完成）

客官°小女子只卖身不卖艺 2021-11-17 05:12 176阅读 0赞

未理解透，鬼知道怎么A的  
蒟蒻交了个乱猜贪心搞了10pts，一翻题解群佬乱舞，最后DP解决  
$\\exists i - next\[i\] <= j, f\[j\] = f\[next\[i\]\] $

#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #define R(a,b,c) for(register int a = (b); a <= (c); ++ a) #define nR(a,b,c) for(register int a = (b); a >= (c); -- a) #define Max(a,b) ((a) > (b) ? (a) : (b)) #define Min(a,b) ((a) < (b) ? (a) : (b)) #define Fill(a,b) memset(a, b, sizeof(a)) #define Abs(a) ((a) < 0 ? -(a) : (a)) #define Swap(a,b) a^=b^=a^=b #define ll long long #define ON_DEBUG #ifdef ON_DEBUG #define D_e_Line printf("\n\n----------\n\n") #define D_e(x) cout << #x << " = " << x << endl #define Pause() system("pause") #define FileOpen() freopen("in.txt","r",stdin); #else #define D_e_Line ; #define D_e(x) ; #define Pause() ; #define FileOpen() ; #endif struct ios{ template<typename ATP>ios& operator >> (ATP &x){ x = 0; int f = 1; char c; for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-') f = -1; while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar(); x*= f; return *this; } }io; using namespace std; const int N = 500007; char str[N]; int nxt[N]; int f[N], pos[N]; int main(){ //FileOpen(); scanf("%s",str + 1); int len = strlen(str + 1); nxt[0] = -1; int j = 0; R(i,2,len){ while(j != -1 && str[j + 1] != str[i]) j = nxt[j]; nxt[i] = ++j; } f[1] = 1; j = 0; R(i,2,len){ f[i] = i; if(pos[f[nxt[i]]] >= i - nxt[i]) f[i] = f[nxt[i]]; pos[f[i]] = i; } printf("%d", f[len]); return 0; }

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转载于:https://www.cnblogs.com/bingoyes/p/11240752.html

[1570282-20190724204546802-1959569462.png]: /images/20211116/9e0fa15921ea4766a0a3ae8db6b6c34b.png